Magnetic Resonance Imaging (MRI) is widely used in clinical practice, but suffered from prolonged acquisition time. Although deep learning methods have been proposed to accelerate acquisition and demonstrate promising performance, they rely on high-quality fully-sampled datasets for training in a supervised manner. However, such datasets are time-consuming and expensive-to-collect, which constrains their broader applications. On the other hand, self-supervised methods offer an alternative by enabling learning from under-sampled data alone, but most existing methods rely on further partitioned under-sampled k-space data as model's input for training, resulting in a loss of valuable information. Additionally, their models have not fully incorporated image priors, leading to degraded reconstruction performance. In this paper, we propose a novel re-visible dual-domain self-supervised deep unfolding network to address these issues when only under-sampled datasets are available. Specifically, by incorporating re-visible dual-domain loss, all under-sampled k-space data are utilized during training to mitigate information loss caused by further partitioning. This design enables the model to implicitly adapt to all under-sampled k-space data as input. Additionally, we design a deep unfolding network based on Chambolle and Pock Proximal Point Algorithm (DUN-CP-PPA) to achieve end-to-end reconstruction, incorporating imaging physics and image priors to guide the reconstruction process. By employing a Spatial-Frequency Feature Extraction (SFFE) block to capture global and local feature representation, we enhance the model's efficiency to learn comprehensive image priors. Experiments conducted on the fastMRI and IXI datasets demonstrate that our method significantly outperforms state-of-the-art approaches in terms of reconstruction performance.
翻译:磁共振成像(MRI)在临床实践中应用广泛,但其数据采集时间较长。尽管已有深度学习方法被提出以加速采集过程并展现出良好性能,但这些方法依赖于高质量全采样数据集进行有监督训练。然而,此类数据集的采集耗时且成本高昂,限制了其更广泛的应用。另一方面,自监督方法提供了一种替代方案,能够仅从欠采样数据中学习,但现有方法大多依赖进一步划分的欠采样k空间数据作为模型训练输入,导致有价值信息的损失。此外,这些模型未能充分融入图像先验,导致重建性能下降。本文提出一种新颖的可重见双域自监督深度展开网络,以解决仅存在欠采样数据集时的上述问题。具体而言,通过引入可重见双域损失函数,训练过程中可利用全部欠采样k空间数据,以减轻因进一步划分造成的信息损失。该设计使模型能够隐式适应所有欠采样k空间数据作为输入。此外,我们基于Chambolle和Pock近端点算法设计了一种深度展开网络(DUN-CP-PPA)以实现端到端重建,通过融入成像物理模型与图像先验来指导重建过程。通过采用空间-频率特征提取模块捕获全局与局部特征表示,我们提升了模型学习全面图像先验的效率。在fastMRI和IXI数据集上的实验表明,本方法在重建性能方面显著优于现有先进方法。